Delivery wire assembly for occlusive device delivery system

ABSTRACT

A core wire of a delivery wire assembly for delivery of an occlusive device to a location in a patient&#39;s vasculature, includes a wire having a polyimide coating, with a polymer jacket disposed around the polyimide coating, and a hypotube disposed around the polymer jacket. The delivery wire assembly further comprises a delivery wire conduit including a coil disposed around the wire, wherein a proximal end of the coil is connected to a distal end of the hypotube. The polyimide coating may be enhanced with a nano-particle or micro-fiber ceramic, such as yttria-stabilized zirconia.

RELATED APPLICATION DATA

The present application claims the benefit under 35 U.S.C. §119 to U.S.provisional patent application Ser. No. 61/261,213, filed Nov. 13, 2009.The foregoing application is hereby incorporated by reference into thepresent application in its entirety.

FIELD

The field of the disclosed inventions generally relates to systems anddelivery devices for implanting vaso-occlusive devices for establishingan embolus or vascular occlusion in a vessel of a human or veterinarypatient. More particularly, the disclosed inventions relate to adelivery wire assembly.

BACKGROUND

Vaso-occlusive devices or implants are used for a wide variety ofreasons, including treatment of intra-vascular aneurysms. Commonly usedvaso-occlusive devices include soft, helically wound coils formed bywinding a platinum (or platinum alloy) wire strand about a “primary”mandrel. The coil is then wrapped around a larger, “secondary” mandrel,and heat treated to impart a secondary shape. For example, U.S. Pat. No.4,994,069, issued to Ritchart et al., describes a vaso-occlusive coilthat assumes a linear, helical primary shape when stretched forplacement through the lumen of a delivery catheter, and a folded,convoluted secondary shape when released from the delivery catheter anddeposited in the vasculature.

In order to deliver the vaso-occlusive devices to a desired site in thevasculature, e.g., within an aneurismal sac, it is well-known to firstposition a small profile, delivery catheter or “micro-catheter” at thesite using a steerable guidewire. Typically, the distal end of themicro-catheter is provided, either by the attending physician or by themanufacturer, with a selected pre-shaped bend, e.g., 45°, 90°, “J”, “S”,or other bending shape, depending on the particular anatomy of thepatient, so that it will stay in a desired position for releasing one ormore vaso-occlusive device(s) into the aneurysm once the guidewire iswithdrawn. A delivery or “pusher” wire is then passed through themicro-catheter, until a vaso-occlusive device coupled to a distal end ofthe delivery wire is extended out of the distal end opening of themicro-catheter and into the aneurysm. The vaso-occlusive device is thenreleased or “detached” from the end delivery wire, and the delivery wireis withdrawn back through the catheter. Depending on the particularneeds of the patient, one or more additional occlusive devices may bepushed through the catheter and released at the same site.

One well-known way to release a vaso-occlusive device from the end ofthe pusher wire is through the use of an electrolytically severablejunction, which is a small exposed section or detachment zone locatedalong a distal end portion of the pusher wire. The detachment zone istypically made of stainless steel and is located just proximal of thevaso-occlusive device. An electrolytically severable junction issusceptible to electrolysis and disintegrates when the pusher wire iselectrically charged in the presence of an ionic solution, such as bloodor other bodily fluids. Thus, once the detachment zone exits out of thecatheter distal end and is exposed in the vessel blood pool of thepatient, a current applied through an electrical contact to theconductive pusher wire completes an electrolytic detachment circuit witha return electrode, and the detachment zone disintegrates due toelectrolysis.

In “monopolar” systems, return electrodes include electrodes attached tothe patient's skin and conductive needles inserted through the skin at aremote site. In “bipolar” systems, return electrodes are located on thepusher wire, e.g. on a delivery wire conduit, but electrically insulatedfrom the conductive path ending in the detachment zone. The anode ismade up of a polyimide insulated core wire, which runs through thepusher wire, is attached to the electrical contact at the proximal end,and forms the detachment zone at the distal end.

Perceived problems with current bipolar vaso-occlusive coil deliverysystems include damage to the polyimide coating resulting from abrasionas the core wire is threaded through the delivery wire conduit duringmanufacturing. Damage to the polyimide coating in a bipolar system canlead to electrical shorts or current leakage in the electrolyticdetachment system. Current leakage (a wet short) occurs when body fluidleaks into the pusher wire and makes contact with the core wire exposedby the imperfections in the insulation. An intermittent or direct hardshort (a dry short) occurs when the exposed core wire makes directcontact with the inside of the pusher wire. Current leakage andelectrical shorts may adversely impact detachment of the occlusivedevice by electrolysis.

SUMMARY

In one embodiment of the disclosed inventions, a delivery wire assemblyis provided for delivery of an occlusive device to a location in apatient's vasculature, the delivery wire assembly including a deliverywire conduit defining a conduit lumen, and a core wire disposed in theconduit lumen, wherein the core wire is at least partially covered withan abrasion resistant coating. By way of non-limiting example, theabrasion resistant coating may be a nano-particle or micro-fiber ceramicenhanced polyimide coating. By way of another, non-limiting example, theabrasion resistant coating is a nano-particle or micro-fiber ceramiclayer covered with a polyimide coating enhanced with a nano-particle ora micro-fiber ceramic. In one embodiment, the abrasion resistant coatingcomprises yttria-stabilized zirconia. In one embodiment, the abrasionresistant coating is a polyimide layer covered with a polymer protectiontube.

In another embodiment of the disclosed inventions, a delivery wireassembly is provided for delivery of an occlusive device to a locationin a patient's vasculature. The assembly includes a delivery wireconduit having an inner wall defining a conduit lumen, the wall at leastpartially comprising an abrasion resistant surface. The assembly furtherincludes a core wire disposed in the conduit lumen. The conduit lumensurface may have a smooth finish at least partially covered with anabrasion resistant coating. In one such embodiment, the abrasionresistant coating comprises a polyimide jacket or coating enhanced witha nano-particle or micro-fiber ceramic, such as yttria-stabilizedzirconia.

In yet another embodiment of the disclosed inventions, a delivery wireassembly is provided for delivery of an occlusive device to a locationin a patient's vasculature, the assembly comprising a core wire and adelivery conduit, the core wire including a wire having a polyimidecoating, with a polymer jacket disposed around the polyimide coating,and a hypotube disposed around the polymer jacket. The delivery conduitincludes a coil disposed around the wire, wherein a proximal end of thecoil is connected to a distal end of the hypotube. The polyimide coatingmay be enhanced with a nano-particle or micro-fiber ceramic, such asyttria-stabilized zirconia.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings in which like reference numbers representcorresponding parts throughout, and in which:

FIG. 1 illustrates an occlusive coil delivery system, according to oneembodiment.

FIG. 2 is a longitudinal cross-sectional view of a delivery wireassembly, according to one embodiment.

FIG. 3 illustrates an occlusive coil in a natural state mode,illustrating one exemplary secondary configuration.

FIGS. 4-6 are detailed longitudinal cross-sectional views of deliverywire assemblies according to various embodiments, each with additionaldetails of the core wire shown in a magnified inset.

FIGS. 7-10 are detailed longitudinal cross-sectional views of deliverywire assemblies according to various embodiments, each with additionaldetails of the delivery wire conduit shown in a magnified inset.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

FIG. 1 illustrates an occlusive coil delivery system 10 according to oneembodiment. The system 10 includes a number of subcomponents orsub-systems. These include a delivery catheter 100, a delivery wireassembly 200, an occlusive coil 300, and a power supply 400. Thedelivery catheter 100 includes a proximal end 102, a distal end 104, anda lumen 106 extending between the proximal and distal ends 102, 104. Thelumen 106 of the delivery catheter 100 is sized to accommodate axialmovement of the delivery wire assembly 200. Further, the lumen 106 issized for the passage of a guidewire (not shown) which may optionally beused to properly guide the delivery catheter 100 to the appropriatedelivery site.

The delivery catheter 100 may include a braided-shaft construction ofstainless steel flat wire that is encapsulated or surrounded by apolymer coating. By way of non-limiting example, HYDROLENE® is a polymercoating that may be used to cover the exterior portion of the deliverycatheter 100. Of course, the system 10 is not limited to a particularconstruction or type of delivery catheter 100 and other constructionsknown to those skilled in the art may be used for the delivery catheter100.

The inner lumen 106 may be advantageously coated with a lubriciouscoating such as PTFE to reduce frictional forces between the deliverycatheter 100 and the respective delivery wire assembly 200 and occlusivecoil 300 being moved axially within the lumen 106. The delivery catheter100 may include one or more optional marker bands 108 formed from aradiopaque material that can be used to identify the location of thedelivery catheter 100 within the patient's vasculature system usingimaging technology (e.g., fluoroscope imaging). The length of thedelivery catheter 100 may vary depending on the particular application,but generally is around 150 cm in length. Of course, other lengths ofthe delivery catheter 100 may be used with the system 10 describedherein.

The delivery catheter 100 may include a distal end 104 that is straightas illustrated in FIG. 1. Alternatively, the distal end 104 may bepre-shaped into a specific geometry or orientation. For example, thedistal end 104 may be shaped into a “C” shape, an “S” shape, a “J”shape, a 45° bend, a 90° bend. The size of the lumen 106 may varydepending on the size of the respective delivery wire assembly 200 andocclusive coil 300, but generally the diameter of the lumen 106 of thedelivery catheter 100 (I.D. of delivery catheter 100) is less than about0.02 inches. The delivery catheter 100 is known to those skilled in theart as a microcatheter. While not illustrated in FIG. 1, the deliverycatheter 100 may be utilized with a separate guide catheter (not shown)that aids in guiding the delivery catheter 100 to the appropriatelocation within the patient's vasculature.

Still referring to FIG. 1, the system 10 includes a delivery wireassembly 200 configured for axial movement within the lumen 106 of thedelivery catheter 100. The delivery wire assembly 200 generally includesa proximal end 202 and a distal end 204. The delivery wire assembly 200includes a delivery wire conduit 213, which has a proximal tubularportion 206 and a distal coil portion 208. The proximal tubular portion206 may be formed from, for example, a flexible stainless steelhypotube. The distal coil portion 208 may be formed from, for example,stainless steel wire. The distal coil portion 208 may be joined to theproximal tubular portion 206 in an end-to-end arrangement.

The delivery wire assembly 200 further includes a core wire 210 thatextends from the proximal end 202 of the delivery wire assembly 200 to alocation that is distal with respect to the distal end 204 of thedelivery wire assembly 200. The core wire 210 is disposed within aconduit lumen 212 that extends within an interior portion of thedelivery wire conduit 213. The distal end of the conduit lumen 212 issealed with a stopper 252. The core wire 210 is formed from anelectrically conductive material such as stainless steel wire. Theproximal end 214 of the core wire 210 (shown in phantom) is electricallycoupled to an electrical contact 216 located at the proximal end 202 ofthe delivery wire assembly 200. The electrical contact 216 may be formedfrom a metallic solder (e.g., gold) that is configured to interface witha corresponding electrical contact (not shown) in the power supply 400.The core wire 210 is connected to the delivery wire conduit 213 asdescribed below. The core wire 210 functions as a tether to theocclusive coil 300, such that when the delivery wire assembly 200 ispulled proximally, the occlusive coil 300 can also be withdrawn prior tocoil detachment.

A portion of the core wire 210 is coated with an insulative coating 218.The entire length of the core wire 210 is coated with an insulativecoating 218, except for the proximal end 214 of the core wire 210 thatcontacts the electrical contact 216, and a small region 220 located in aportion of the core wire 210 that extends distally with respect to thedistal end 204 of the delivery wire assembly 200. This latter, “bare”portion of the core wire 210 forms the electrolytic detachment zone 220,which dissolves upon application of electrical current from the powersupply 400.

In some embodiments, the insulative coating 218 is also abrasionresistant. For instance, in the embodiment in FIG. 4, the insulative andabrasion resistant coating 218 includes a polyimide layer 254strengthened with biocompatible ceramic materials, such asyttria-stablized zirconia (“YSZ”). The ceramic materials are formed intonano-particles or micro-fibers and incorporated into the polyimide layer254. The YSZ increases the abrasion resistance of the polyimide and theelectrical insulation performance, because, in addition to hardness, YSZalso has a high dielectric constant.

In the embodiment in FIG. 5, the insulative and abrasion resistantcoating 218 includes a layer 256 of nano-particles or micro-fibers ofbiocompatible ceramic materials, such as YSZ is bonded to the core wire210. Then a polyimide layer 254 is bonded on top of the ceramic layer256. The polyimide layer 254 can also be strengthened with biocompatibleceramic materials as described above.

In the embodiment in FIG. 6, the insulative and abrasion resistantcoating 218 includes a polyimide layer 254 bonded to the core wire 210.Then the polyimide layer 254 coated core wire 210 is encased in apolymer (i.e., polyimide) protection tube jacket 258. The polyimidecomponents 254, 258 can also be strengthened with biocompatible ceramicmaterials as described above.

In the embodiment in FIG. 7, the insulative and abrasion resistantcoating 218 in the proximal tubular portion 206 of the delivery wireconduit 213 includes a polyimide layer 254 bonded to the core wire 210.Then the polyimide layer 254 coated core wire 210 is encased in apolymer (i.e., polyimide) protection tube jacket 258 and a metalhypotube 260 in one step, using forming mills and welding lasers. Thepolyimide components 254, 258 can also be strengthened withbiocompatible ceramic materials as described above.

In other embodiments, the inner surface 264 of the hypotube 260 in theproximal tubular portion 206 of the delivery wire conduit 213 is treatedto reduce abrasion to the insulative coating 218 of the core wire 210.For instance, in the embodiment in FIG. 8, the inner surface 264 of thehypotube 260 has been treated with enhanced finishing, resulting in asmoother surface.

In the embodiment in FIG. 9, the inner surface 264 of the hypotube 260is covered with a polymer (i.e., polyimide) protection tube jacket 258.The polyimide components 254, 258 can also be strengthened withbiocompatible ceramic materials as described above.

In the embodiment in FIG. 10, the inner surface 264 of the hypotube 260is covered with a polyimide coating 266. The polyimide coating 266 canalso be strengthened with biocompatible ceramic materials as describedabove.

FIG. 2 illustrates a longitudinal cross-sectional view of the deliverywire assembly 200 according to one embodiment. Similar elements of thisembodiment are identified with the same reference numbers as discussedabove with respect to FIG. 1. The delivery wire assembly 200 includes aproximal end 202 and a distal end 204 and measures between around 184 cmto around 186 cm in length. The delivery wire assembly 200 includes adelivery wire conduit 213 with a proximal tubular portion 206, a distalcoil portion 208, and a distal opening 201. The proximal tubular portion206 may be formed from stainless steel hypotube having an outer diameter(OD) of 0.01325 inches and inner diameter (ID) of 0.0075 inches. Thelength of the hypotube section may be between around 140 cm to around150 cm.

As seen in FIG. 2, a distal coil portion 208 is joined in end-to-endfashion to the distal face of the proximal tubular portion 206. Thejoining may be accomplished using a weld or other bond. The distal coilportion 208 may have a length of around 39 cm to around 41 cm in length.The distal coil portion 208 may comprise a coil of 0.0025 inches×0.006inches. The first dimension generally refers to the OD of the coil wirethat forms the coil. The latter dimension generally refers to theinternal mandrel used to wind the coil wire around to form the pluralityof coil winds and is the nominal ID of the coil.

One or more marker coils 205 of the distal coil portion 208 may beformed from a radiopaque material. For example, the distal coil portion208 may include a segment of stainless steel coil (e.g., 3 cm inlength), followed by a segment of platinum coil (which is radiopaque andalso 3 mm in length), followed by a segment of stainless steel coil(e.g., 37 cm in length), and so on and so forth.

An outer sleeve 262 or jacket surrounds a portion of the proximaltubular portion 206 and a portion of the distal coil portion 208 of thedelivery wire conduit 213. The outer sleeve 262 covers the interface orjoint formed between the proximal tubular portion 206 and the distalcoil portion 208. The outer sleeve 262 may have a length of around 50 cmto around 54 cm. The outer sleeve 262 may be formed from a polyetherblock amide plastic material (e.g., PEBAX 7233 lamination). The outersleeve 262 may include a lamination of PEBAX and HYDROLENE® that may beheat laminated to the delivery wire assembly 200. The OD of the outersleeve 262 may be less than 0.02 inches and advantageously less than0.015 inches.

The core wire 210, which runs through the delivery wire conduit 213,terminates at electrical contact 216 at one end and extends distallywith respect to the distal coil portion 208 of the delivery wire conduit213 to the core wire distal end 222 at the other end. The core wire 210is coated with an insulative (or insulative and abrasion resistant)coating 218 except at the electrolytic detachment zone 220 and theproximal segment coupled to the electrical contact 216. The electrolyticdetachment zone 220 is located less and half a millimeter (e.g., about0.02 mm to about 0.2 mm) distally with respect to the distal end of thedistal coil portion 208. The core wire 210 may have an OD of around0.00175 inches.

FIG. 3 illustrates one exemplary configuration of an occlusive coil 300in a natural state. In the natural state, the occlusive coil 300transforms from the straight configuration illustrated in, for instance,FIG. 1 into a secondary shape. The secondary shaped may include both twoand three dimensional shapes of a wide variety. FIG. 3 is just oneexample of a secondary shape of an occlusive coil 300 and other shapesand configurations are contemplated to fall within the scope of thedisclosed inventions. Also, the occlusive coil 300 may incorporatesynthetic fibers over all or a portion of the occlusive coil 300 as isknown in the art. These fibers may be attached directly to coil windings308 or the fibers may be integrated into the occlusive coil 300 using aweave or braided configuration.

The occlusive coil 300 includes a proximal end 302, a distal end 304,and a lumen 306 extending there between. The occlusive coil 300 isgenerally made from a biocompatible metal such as platinum or a platinumalloy (e.g., platinum-tungsten alloy). The occlusive coil 300 generallyincludes a straight configuration (as illustrated in FIG. 1) when theocclusive coil 300 is loaded within the delivery catheter 100. Uponrelease, the occlusive coil 300 generally takes a secondary shape whichmay include three-dimensional helical configurations such as thoseillustrated in FIG. 3.

The occlusive coil 300 includes a plurality of coil windings 308. Thecoil windings 308 are generally helical about a central axis disposedalong the lumen 306 of the occlusive coil 300. The occlusive coil 300may have a closed pitch configuration as illustrated in FIG. 1. Ofcourse, the system 10 described herein may be used with occlusive coils300 or other occlusive structures having a variety of configurations,and is not limited to occlusive coils 300 having a certain size orconfiguration. Additional features or components might be used toprovide mechanical interlock between the delivery wire 200 and occlusivecoil 300.

The distal end 222 of the core wire 210, which includes the electrolyticdetachment zone 220, is connected to the proximal end 302 of theocclusive coil 300 at a junction 250. Various techniques and devices canbe used to connect the core wire 210 to the occlusive coil 300,including laser melting, and laser tack, spot, and continuous welding.It is preferable to apply an adhesive 240 to cover the junction 250formed between the distal end 222 of the core wire 210 and the proximalend 302 of the occlusion coil 300. The adhesive 240 may include an epoxymaterial which is cured or hardened through the application of heat orUV radiation. For example, the adhesive 240 may include a thermallycured, two-part epoxy such as EPO-TEK® 353ND-4 available from EpoxyTechnology, Inc., 14 Fortune Drive, Billerica, Mass. The adhesive 240encapsulates the junction 250 and increases its mechanical stability.

As shown in FIG. 1, the system 10 further includes a power supply 400for supplying direct current to the core wire 210, which contains theelectrolytic detachment zone 220. In the presence of an electricallyconductive fluid (including a physiological fluid such as blood, or anelectrically conductive flushing solution such as saline), activation ofthe power supply 400 causes electrical current to flow in a circuitincluding the core wire electrical contact 216, the core wire 210, theelectrolytic detachment zone 220, and a return electrode (not shown).After several seconds (generally less than about 10 seconds), thesacrificial electrolytic detachment zone 220 dissolves, and theocclusive coil 300 separates form the core wire 210.

The power supply 400 preferably includes an onboard energy source, suchas batteries (e.g., a pair of AAA batteries), along with drive circuitry402. The drive circuitry 402 may include one or more microcontrollers orprocessors configured to output a driving current. The power supply 400illustrated in FIG. 1 includes a receptacle 404 configured to receiveand mate with the proximal end 202 of the delivery wire assembly 200.Upon insertion of the proximal end 202 into the receptacle 404, theelectrical contact 216 disposed on the delivery wire assembly 200electrically couple with corresponding contacts (not shown) located inthe power supply 400.

A visual indicator 406 (e.g., LED light) is used to indicate when theproximal end 202 of delivery wire assembly 200 has been properlyinserted into the power supply 400. Another visual indicator 407 isactivated if the onboard energy source needs to be recharged orreplaced. The power supply 400 includes an activation trigger or button408 that is depressed by the user to apply the electrical current to thesacrificial electrolytic detachment zone 220. Once the activationtrigger 408 has been activated, the driver circuitry 402 automaticallysupplies current until detachment occurs. The drive circuitry 402typically operates by applying a substantially constant current, e.g.,around 1.5 mA.

The power supply 400 may include optional detection circuitry 410 thatis configured to detect when the occlusive coil 300 has detached fromthe core wire 210. The detection circuitry 410 may identify detachmentbased upon a measured impedance value. A visual indicator 412 mayindicate when the power supply 400 is supplying adequate current to thesacrificial electrolytic detachment zone 220. Another visual indicator414 may indicate when the occlusive coil 300 has detached from the corewire 210. As an alternative to the visual indicator 414, an audiblesignal (e.g., beep) or even tactile signal (e.g., vibration or buzzer)may be triggered upon detachment. The detection circuitry 410 may beconfigured to disable the drive circuitry 402 upon sensing detachment ofthe occlusive coil 300.

The power supply 400 may also contain another visual indicator 416 thatindicates to the operator when non-bipolar delivery wire assembly isinserted into the power supply 400. As explained in the backgroundabove, non-bipolar delivery wire assemblies use a separate returnelectrode that typically is in the form of a needle that was insertedinto the groin area of the patient. The power supply 400 is configuredto detect when a non-bipolar delivery wire assembly has been inserted.Under such situations, the visual indicator 416 (e.g., LED) is turned onand the user is advised to insert the separate return electrode (notshown in FIG. 1) into a port 418 located on the power supply 400.

Still referring to FIG. 1, the core wire 210 forms a first conductivepath 242 between the electrical contact 216 and the electrolyticdetachment zone 220. This first conductive path 242 may comprise theanode (+) of the electrolytic circuit when the delivery wire assembly200 is operatively coupled to the power supply 400. A second conductivepath 244, the return path, is formed by the proximal tubular portion 206and a distal coil portion 208 of the delivery wire conduit 213. Thesecond conductive path 244 is electrically isolated from the firstconductive path 242. The second conductive path 244 may comprise thecathode (−) or ground electrode for the electrical circuit.

A ground contact 246 for the second conductive path 244 may be disposedon a proximal end of the tubular portion 206 of the delivery wireconduit 213. In one embodiment, the ground contact 246 is simply anexposed portion of the tubular portion 206 since the tubular portion 206is part of the second conductive path 244. For instance, a proximalportion of the tubular portion 206 that is adjacent to the electricalcontact 216 may be covered with an insulative coating 207 such aspolyimide as illustrated in FIG. 2. An exposed region of the tubularportion 206 that does not have the insulative coating may form theground contact 246. Alternatively, the ground contact 246 may be a ringtype electrode or other contact that is formed on the exterior of thetubular portion 206.

The ground contact 246 is configured to interface with a correspondingelectrical contact (not shown) in the power supply 400 when the proximalend 202 of the delivery wire assembly 200 is inserted into the powersupply 400. The ground contact 246 of the second conductive path 244 is,of course, electrically isolated with respect to the electrical contact216 of the first conductive path 242.

While various embodiments of the disclosed inventions have been shownand described, they are presented for purposes of illustration, and notlimitation. Various modifications may be made to the illustrated anddescribed embodiments (e.g., the dimensions of various parts) withoutdeparting from the scope of the disclosed inventions, which is to belimited and defined only by the following claims and their equivalents.

1. A delivery wire assembly for delivering an occlusive device to alocation in a patient's vasculature, comprising: a delivery wire conduitdefining a conduit lumen; and a core wire disposed in the conduit lumen,wherein the core wire is at least partially covered with an abrasionresistant coating.
 2. The delivery wire assembly of claim 1, wherein theabrasion resistant coating is a nano-particle or micro-fiber ceramicenhanced polyimide coating.
 3. The delivery wire assembly of claim 1,wherein the abrasion resistant coating is a nano-particle or micro-fiberceramic layer covered with a polyimide coating enhanced with anano-particle or a micro-fiber ceramic.
 4. The delivery wire assembly ofclaim 1, wherein the abrasion resistant coating comprisesyttria-stabilized zirconia.
 5. The delivery wire assembly of claim 1,wherein the abrasion resistant coating is a polyimide layer covered witha polymer protection tube.
 6. A delivery wire assembly for delivering anocclusive device to a location in a patient's vasculature, comprising: adelivery wire conduit defining a conduit lumen, the conduit lumendefined by a lumen wall at least partially comprising an abrasionresistant surface; and a core wire disposed in the conduit lumen.
 7. Thedelivery wire assembly of claim 6, wherein the conduit lumen surface hasa smooth finish.
 8. The delivery wire assembly of claim 6, wherein theconduit lumen surface is at least partially covered with an abrasionresistant coating.
 9. The delivery wire assembly of claim 8, wherein theabrasion resistant coating comprises a polyimide jacket or coating. 10.The delivery wire assembly of claim 9, wherein the polyimide jacket orcoating is enhanced with a nano-particle or micro-fiber ceramic.
 11. Thedelivery wire assembly of claim 10, wherein the ceramic isyttria-stabilized zirconia.
 12. A delivery wire assembly for deliveringan occlusive device to a location in a patient's vasculature, comprisinga core wire and a delivery conduit, the core wire comprising a wire, apolyimide coating disposed around the wire, a polymer jacket disposedaround the polyimide coating, and a hypotube disposed around the polymerjacket; and the delivery wire conduit comprising a coil disposed aroundthe wire having a polyimide coating, the coil having a proximal endconnected to the hypotube distal end.
 13. The delivery wire assembly ofclaim 12, wherein the polyimide coating is enhanced with a nano-particleor micro-fiber ceramic.
 14. The delivery wire assembly of claim 13,wherein the ceramic is yttria-stabilized zirconia.